5971 Two Piece Ion Focus Lens

[benhutcherson]

I've been meaning to ask about this one for a while.

I have a 5971 that I pulled out of storage a few months back and have posted about here a few times. Overall, it has worked well, or at least it did after sitting under vacuum for a week or two.

I noticed this when I gave it a once over before putting it into service, though-rather than the one piece ion focus lens I've seen on every other 5971 I've serviced, this one is in two pieces-a cylinder and then just a flat plate with a hole in the center. Both are nested into the same slot in the vespal insulators, and there's a springy gold-plated wire that goes between them.

Has anyone encountered this construction before? It seems to work fine, but is also a bit of a pain to put back together.

[James_Ball]

Didn't get the image, but if I remember correctly that was what was originally used, then not long after they 5971 came out they changed it to one piece. Either that or it was for the GCD, which has most parts interchangeable with the 5971.

Maybe you have something rare there.

[LALman]

That is a very interesting construction. I suppose it might be easier to clean. Is the ion focus lens just a straight cylinder? or does the ion focus cylinder converge down to a diameter at one end that matches the plate in the middle?

[benhutcherson]

Thanks guys. As I said, I've not seen this arrangement before. I'm pretty sure-but couldn't swear to it-that the top board is dated '92, which if I'm not mistaken should have been close to the end of production on the 5971. The GC also carries that date, and it is all EPC controlled(single injector)-it's a bit strange to have a 5890 without a head pressure gauge on the front, but it's certainly nice when you actually use it.

It's just a hollow cylinder with a consistent inside diameter and the two "steps" shown on the outside. I can't tell that either end is any different. And yes, it certainly is easy to clean!

[James_Ball]

Thanks guys. As I said, I've not seen this arrangement before. I'm pretty sure-but couldn't swear to it-that the top board is dated '92, which if I'm not mistaken should have been close to the end of production on the 5971. The GC also carries that date, and it is all EPC controlled(single injector)-it's a bit strange to have a 5890 without a head pressure gauge on the front, but it's certainly nice when you actually use it.

It's just a hollow cylinder with a consistent inside diameter and the two "steps" shown on the outside. I can't tell that either end is any different. And yes, it certainly is easy to clean!

What year did they begin to produce the 5971? I thought the 5970 was produced up until about 1988/89. We purchased our last 5971 in about 1993 and first 5972 about 1995, if my failing memory still serves me at all, though I doubt that sometimes

[benhutcherson]

What year did they begin to produce the 5971? I thought the 5970 was produced up until about 1988/89. We purchased our last 5971 in about 1993 and first 5972 about 1995, if my failing memory still serves me at all, though I doubt that sometimes

That I don't know, but 1990 sounds about right to me.

Funny enough, I actually emailed Brenda yesterday with a 5971 question(whether or not to grease the o-ring-she said yes) and she seemed impressed that we had an operational one. In her words "that may be the last one around" and also wanted to know if we wanted to replace it . I personally have handled two others still in service in the last year, so they certainly are out there.

[James_Ball]

What year did they begin to produce the 5971? I thought the 5970 was produced up until about 1988/89. We purchased our last 5971 in about 1993 and first 5972 about 1995, if my failing memory still serves me at all, though I doubt that sometimes

That I don't know, but 1990 sounds about right to me.

Funny enough, I actually emailed Brenda yesterday with a 5971 question(whether or not to grease the o-ring-she said yes) and she seemed impressed that we had an operational one. In her words "that may be the last one around" and also wanted to know if we wanted to replace it . I personally have handled two others still in service in the last year, so they certainly are out there.

If you really want to get her fired up, just tell her you just bought a 5995 and want to know if she can help you get it going.

Be sure to duck right after asking

[LALman]

What year did they begin to produce the 5971? I thought the 5970 was produced up until about 1988/89. We purchased our last 5971 in about 1993 and first 5972 about 1995, if my failing memory still serves me at all, though I doubt that sometimes

That I don't know, but 1990 sounds about right to me.

Funny enough, I actually emailed Brenda yesterday with a 5971 question(whether or not to grease the o-ring-she said yes) and she seemed impressed that we had an operational one. In her words "that may be the last one around" and also wanted to know if we wanted to replace it . I personally have handled two others still in service in the last year, so they certainly are out there.

I still have mine in service mostly as a backup if my 5973 goes down. I had my hightemp diffusion pump sensor go out and replaced the filiments with the yttria coated. That was a mistake. So I just tore it all down again and am having trouble getting it back up. Apparently did got get source cleaned enough.

[LALman]

Another thing about these 5980 Series II GC's is that they are very finicky and leaky compared to the 6890's. If any of you have a clever fix for the wonky gas fittings in the Series II, I'd like to know about them.

The Series II in my 5971/5890 GC-MS can only do constant flow. I keep eyeing my other Series II 5890 that has pulse and variable flow (its a GC-FID backup for my 6890 GC-FID) and wondering if I could put it together with the 5971 but I think there would be firmware issues that make it difficult if not impossible.